Practice question · True or false
The atomic number of an element equals the number of protons in its nucleus.
Hints
- Ask which particle count is the one that fixes an element's identity.
- Neutrons vary between isotopes, so they cannot be the defining count.
Show the answer
True
Why
The atomic number Z uniquely identifies an element and equals the proton count. The mass number also includes neutrons.
Practise Atomic structure and quantized description
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